SEARCH

SEARCH BY CITATION

As part of scientific activities of the Middle Atmosphere Program in Japan, the direct sampling of trace gases and aerosols in the lower stratosphere has been planned by using Merlin-IV aircraft. Most of the flights have been performed during winter, since Merlin-IV can reach the lower stratosphere only during cold seasons at latitudes of 36°–40°N. During the sampling flights, concurrent with the aerosol sampling, O3 mixing ratios were measured simultaneously from aircraft by using a modified airborne ozonesonde. The O3 mixing ratio is used as tracer of stratospheric air and, together with radiosonde records of the Japan Meteorological Agency's local weather stations is a good indicator of the height of the tropopause along the flight track.